In treating many illnesses and injuries, it is often useful to replace or reinforce damaged or injured tissues with a biocompatible graft material. Examples of such graft materials are diverse and include, but are not limited to: coronary grafts, such as arteries, veins, and valves; structural tissues, such as ligaments and tendons, dura mater, and skin. The suitable graft materials may also be used for surgical procedures such as slings for the treatment of urinary incontinence, bulking agents for cosmetic or reconstructive surgery, heart valve replacements, pericardium repairs, arterial transplants, and surgical meshes for the repair of hernias, abdominal wall reconstructions, and pelvic floor reconstructions. Suitable graft materials may be derived from allogenic or exogenic sources. Furthermore, allogenic graft materials may further be derived from autologous or homologous sources and may even include cadaveric sources.
The use of biocompatible grafts is an important and sometimes indispensable part of a course of treatment. However, to avoid, dangerously adverse reactions in a patient being treated with a biocompatible graft, it is first necessary to treat a freshly harvested graft material before it may be used as intended. This is particularly true where graft materials are derived from exogenic and homologous sources. Typically autologous sources of graft material represent a much lower risk with regard to adverse reactions but treatment may still be desired for the graft material to further reduce the likelihood of adverse reactions.
Freshly harvested graft materials are treated to remove any type of reactive material that may be present in the graft material, such as antigens, viruses and prions. Once such reactive material is removed, the graft may be emplaced. Removal of reactive cellular materials leaves behind an immunologically inert structural component of the graft alone. The structural component of a graft is an extra cellular matrix comprised of collagen fibers that are by themselves typically biochemically inert. The failure to remove reactive cellular material from the extra cellular matrix can cause severe reactions to the graft material that can extend healing time or even result in the complete rejection of the graft material itself.
Much work has been done in the field of decellularizing human and animal tissue to yield an essentially inert extra cellular matrix useful as a graft material. Typically, other technologies essentially use crosslinking or alkylation to mask the antigens or enzymes or caustic solutions to remove the antigens. While these methods may produce useful biocompatible graft materials, these methods have limitations in terms of their complexity, their expense, their ability to remove (rather than mask) antigens, their ability to remove hair, or controlling the rate of absorption.